1. Field of the Invention
The invention relates to railway cars and particularly to a roof and partition sheet structure in the area of a roof step, upstanding coaming and hatch opening.
2. Description of the Prior Art
The prior art includes U.S. Pat. No. 1,101,824 which discloses a carline of channel bars of a certain configuration with a cutaway portion to form an access into the channel.
The prior art also includes partition sheet assemblies that divide covered railway hopper cars into compartments. The partition sheet assemblies are attached at their upper portions to overhead framing members usually by welding. When the partition sheet assemblies are subjected to a force they are caused to flex. It is this cyclic flexing which causes hard spots and stress concentrations culminating in fatigue fractures in the upper areas of the partition sheets of the prior art.
The present invention is an improvement over the prior art by the inclusion of elongated openings in the partition sheet assemblies in the areas of high stress concentrations reducing stiffness in those areas thereby relieving stress concentrations and improving fatigue characteristics, while still allowing the partition sheet assemblies to act as a roof support element and a stiffening element for the top framing bar.